Recently, studies are actively carried out to understand brain functions and treat brain diseases by stimulating cranial nerves of a subject and detecting and analyzing signals in response thereto.
In order to directly stimulate the cranial nerves of the subject and acquire information therefrom, a neural probe that can be inserted into the body of the subject is used. Also, a microminiature neural probe with an electrode array integrated was developed to detect as much information as possible.
In general, existing neural probes apply electrical stimulus to the cranial nerves by using electrodes arranged on the probe body. However, the application of electrical stimulus to the cranial nerves may damage the cranial nerves. In addition, since the brain is composed of electrically conducting matter, it is impossible to locally stimulate a desired site.
Thus, application of optical stimulus to the cranial nerves and collection of response signals thereto are preferred recently.
Generally, an optical stimulation probe for applying the optical stimulus is composed of a silicon probe body with an optical fiber attached thereto for insertion into the brain, which makes precise control of the stimulation site difficult and is inevitably accompanied by large probe size.
In this regard, a neural probe with an optical waveguide for optical transmission was proposed. However, the procedure for manufacturing the probe is very complicated and the probe structure is also complex.